Document:Tim Paterson 05-Feb-2024 Email
From: Tim Paterson
To: Richard Cini
Date: Mon, 5 Feb 2024 11:45 -0800
Subject: RE: Research project: looking for prior versions of 86-DOS code
I had heard about the discovery of a DOS 0.11C disk (“C” for Cromemco), and was amazed that such an old version was found. The oldest stuff I’ve kept is v1.25. As you probably know, I provided that source code to MSFT a while back and that’s what they’ve posted on GitHub.
I glanced through some of the links and have a couple of random comments:
You mention a file transfer program, but I’m pretty sure that at least until the first release of DOS in August 1980[a], sending disks by Delta Dash was the only way updates were delivered to IBM. (I worked at MSFT May 1980[b] – March 1981[c].)
The Chess program was Sargon. We had it running on my Z80 computer in college ca. 1978. I used the source code translator to port it to DOS.
My development process at SCP began, of course, using CP/M tools. I wrote the 8086 assembler hosted on Cromemco CDOS. I used it to write the Monitor, which lived in ROM on the CPU Support board. I used MicroPro WordMaster (not WordStar) as my editor. When bringing up DOS, I would use CP/M tools to write the binary to the first sectors of the disk, then boot it with the Monitor. The first working version of DOS was 0.10, but a bug was quickly found and 0.11 was, I think, the first released publicly.
Once DOS was fully functional, I needed a better editor to use it. I used a good Z80 disassembler on WordMaster, verifying I could rebuild it for CP/M. Then I set the translator loose on it and it was ported to DOS. So my ongoing development of DOS at SCP took place on an 8086 using my tools and the translated WordMaster. The translator was also how the assembler (and the translator) were originally ported. I’ve often though that I may the only one who took advantage of translation compatibility.
I don’t think I can be much more help on those early versions.
Tim Paterson